Terminal configuration for a battery pack

ABSTRACT

A battery pack, an electrical combination and a method of operating a battery pack. The battery pack may include a housing; a plurality of battery cells supported by the housing; a plurality of terminals including a positive power terminal, a negative power terminal, and a low power terminal; a low power circuit connecting the plurality of battery cells to the low power terminal and the negative terminal to output a first voltage; and a power circuit connecting the plurality of battery cells to the positive power terminal and the negative terminal to output a second voltage, the second voltage being greater than the first voltage. A terminal block for one of a battery pack and an electrical device may include a terminal with a terminal blade, and a terminal support portion.

RELATED APPLICATION

This application is a division of U.S. patent application Ser. No.15/934,798, filed Mar. 23, 2018, which claims the benefit of U.S.Provisional Patent Application No. 62/475,951, filed Mar. 24, 2017, theentire content of each of which is hereby incorporated by reference.

FIELD

The present invention relates to battery packs and electrical devicesconnectable to battery packs and, more particularly, to a terminalconfiguration for a battery pack and/or an electrical device.

SUMMARY

Tools, such as power tools (e.g., drills, drivers, saws, etc.), outdoortools (e.g., blowers, trimmers, etc.), etc., and other electricaldevices (e.g., motorized devices, non-motorized devices, chargers, etc.)(generally referred to herein as “devices” or a “device”) may transferpower (e.g., be powered by, supply power to) with rechargeable batterypacks. The battery pack may be detached from a device for charging orfor use with other devices. In many cases, battery packs are designedsuch that the same battery pack may be used with many kinds of devices.

Battery packs include a number of battery cells (for example, Li-ion,NiCd, NiMH, etc.) connected in a series configuration, a parallelconfiguration, or a combination thereof. Power terminals are connectedto the battery cells. When a battery pack is connected to a device, thepower terminals of the battery pack are connected to corresponding powerterminals of the device, and the battery pack provides operating powerto the device through the power terminals.

Many electrical devices include a controller to monitor and controloperation (e.g., motor speed, torque output, etc.) of the device.Similarly, many battery packs include a controller to monitor andcontrol operation (e.g., charging and discharging operations, displaystate-of-charge, etc.).

While the device controller and the battery pack controller generallyoperate independently of each other, communication between thecontrollers may be advantageous. For example, the controllers maycommunicate to adjust operation based on a characteristic of the deviceand/or of the battery pack. As another example, the device controllermay communicate with the battery pack controller to authenticate thebattery pack, thereby improving the operation and security of thedevices.

In some embodiments, the power terminals may be used to providecommunication between the device controller and the battery packcontroller. However, this may result in noise being generated on thecommunication line between the controllers. In addition, the amount ofinformation that may be exchanged may be limited by the number ofterminals. Accordingly, separate communication terminals that areisolated from the power terminals may be needed to provide a low-noisecommunication line with sufficient information capacity between thedevice controller and the battery pack controller.

In addition, the power received from the battery pack is used to powerboth the load (e.g., the motor) and the device controller. Whilecontrollers used in electrical devices generally have low powerrequirements, they do consume power. As such, the device controller maybe put into a sleep mode to avoid unnecessarily draining the batterypack to constantly power the device controller.

Electrical device controllers also generally have low power capacity.For example, a device load (e.g., a motor) may operate in a range of25-35 Amps (A) or more. In contrast, a device controller may operate atwell under 1 A. When initiating operation of an electrical device, itmay be desirable to provide low power to “wake-up” the device controllerbefore the full voltage of the battery pack is provided to power theelectrical device.

In some embodiments, a separate dedicated battery (e.g., a coin cell)may be used to power low power functions of the electrical device or thebattery pack. The dedicated battery may be used separately from thebattery pack to power the device controller. However, such a dedicatedbattery adds a separate non-chargeable or non-replaceable component tothe electrical device.

In other embodiments, low power may be provided to the electrical devicethrough a low-power circuit connected across a single battery of thebattery pack. However, this may result in cell balancing issues, as onebattery cell (the “low-power cell”) is drained more often than the otherbattery cells in the battery pack, reducing the service life of thebattery pack. In order to avoid these issues, the single cell low powerapplication may be limited to very low power and infrequent operations.

Accordingly, a relatively low-power power source may be needed to powerrecurring low power functions of the electrical device without incurringperformance or service life issues (e.g., due to cell imbalances) oradding additional non-chargeable, non-replaceable components to thebattery pack or electrical device. A low-power power supply may beadvantageous in powering other low-power components of an electricaldevice, such as an indicator/LED, a communication module, etc.

In one independent aspect, a battery pack may generally include ahousing; a plurality of battery cells supported by the housing; aplurality of terminals including a positive power terminal, a negativepower terminal, and a low power terminal; a low power circuit connectingthe plurality of battery cells to the low power terminal and thenegative terminal to output a first voltage; and a power circuitconnecting the plurality of battery cells to the positive power terminaland the negative terminal to output a second voltage, the second voltagebeing greater than the first voltage (e.g., 80 V compared to 5 V).

In some embodiments, the low power circuit may include a transformer(e.g., a step down transformer or a low dropout regulator (LDO)). Insome embodiments, the battery pack may include a controller operable tocontrol the battery pack to selectively output the first voltage and thesecond voltage.

In another independent aspect, a method of operating a battery-powereddevice with a battery pack may be provided. The device may include adevice housing, a load supported by the device housing, and a devicecontroller supported by the device housing. The battery pack may includea pack housing, and a plurality of battery cells supported by thehousing. The method may generally include supplying a first voltage fromthe plurality of battery cells to the device to power the devicecontroller; and supplying a second voltage from the plurality of batterycells to the device to power the device. Supplying a first voltage mayinclude, with a transformer (e.g., a step down transformer or a lowdropout regulator (LDO)), reducing a voltage of the plurality of batterycells to the first voltage.

In yet another independent aspect, a battery pack may generally includea housing; a plurality of battery cells supported by the housing; acontroller; and a plurality of terminals including a positive powerterminal, a negative power terminal and a communication terminal, thecommunication terminal being electrically connected to the controllerand operable to communicate between the controller and an externaldevice, the communication terminal being isolated from the positivepower terminal and the negative power terminal.

In some embodiments, the housing may include a terminal block supportingthe plurality of terminals, the positive power terminal and the negativeterminal being arranged in a first row, the communication terminal beingarranged in a second row spaced from the first row.

In a further independent aspect, an electrical combination may generallyinclude an electrical device including a device housing, a loadsupported by the device housing, a device controller supported by thedevice housing, and a plurality of device terminals including a devicepositive power terminal, a device negative terminal, and a device lowpower terminal; and a battery pack including a pack housing; a pluralityof battery cells supported by the pack housing, a plurality of packterminals including a pack positive power terminal electricallyconnectable to the device positive power terminal, a pack negative powerterminal electrically connectable to the device negative terminal, and apack low power terminal electrically connectable to the device low powerterminal, a low power circuit connecting the plurality of battery cellsto the low power terminal and the pack negative terminal to output afirst voltage to power the device controller, and a power circuitconnecting the plurality of battery cells to the pack positive powerterminal and the pack negative terminal to output a second voltage topower the load, the second voltage being greater than the first voltage.

In another independent aspect, a terminal for one of a battery pack andan electrical device electrically connectable to the battery pack alongan axis may be provided. The terminal may generally include a terminalblade extending along the axis and having opposite axially-extendingfaces connected by opposite axially-extending edges; and a terminalsupport portion extending transverse to the axis and beyond anassociated face.

In some embodiments, the terminal support portion may include atransverse wing connected to one edge. In some embodiments, the supportportion includes at least one rib on the associated face.

In yet another independent aspect, a terminal block for one of a batterypack and an electrical device electrically connectable to the batterypack along an axis may be provided. The terminal block may generallyinclude a housing; and a plurality of terminals including a positivepower terminal and a ground terminal, at least one terminal including aterminal blade extending along the axis and having oppositeaxially-extending faces connected by opposite axially-extending edges,and a terminal support portion extending transverse to the axis andbeyond an associated face.

In a further independent aspect, an electrical combination may generallyinclude a battery pack including a pack housing, a plurality of batterycells supported by the pack housing, and a pack terminal electricallyconnected to the battery cells; and an electrical device including adevice housing, a circuit supported by the device housing, and a deviceterminal electrically connected to the circuit and electricallyconnectable to the pack terminal to electrically connect the circuit toone or more battery cells; one of the pack terminal and the deviceterminal including a terminal blade extending along the axis and havingopposite axially-extending faces connected by opposite axially-extendingedges, and a terminal support portion extending transverse to the axisand beyond an associated face.

Other independent aspects of the invention may become apparent byconsideration of the detailed description, claims and accompanyingdrawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a battery pack.

FIG. 2 is a plan view of a terminal block of the battery pack of FIG. 1.

FIG. 3 is a block diagram of the battery pack of FIG. 1.

FIG. 4 is a circuit diagram of a low-current supply circuit of alow-power circuit of the battery pack of FIG. 1.

FIG. 5 is a block diagram of a voltage regulator of the low-currentsupply circuit of FIG. 4.

FIG. 6 is a circuit diagram of a low-current supply circuit of alow-power circuit of the battery pack of FIG. 1.

FIG. 7 is a block diagram of a high-current supply circuit of alow-power circuit of the battery pack of FIG. 1.

FIG. 8 is a circuit diagram of a startup circuit of the high-currentsupply circuit of FIG. 7.

FIG. 9 is a plan view of a terminal block of an electrical device.

FIG. 10 is a block diagram of the electrical device.

FIG. 11 is a plan view of a terminal block of a charger.

FIG. 12 is a block diagram of the charger.

FIG. 13 is a flowchart illustrating a quick re-authentication processbetween a battery pack and an electrical device.

FIG. 14 is a flowchart illustrating a transmitter function of a batterytransceiver of the battery pack of FIG. 1.

FIG. 15 is a flowchart illustrating a receiver function of a batterytransceiver of the battery pack of FIG. 1.

FIG. 16 is an isometric view of a terminal block of an electricaldevice.

FIG. 17 is an isometric view of a terminal block of the battery pack ofFIG. 1.

FIG. 18 is an isometric view of a terminal block of an electricaldevice.

FIG. 19 is a perspective view of a connection between the terminal blockof the power of FIG. 18 with a terminal block of the battery pack ofFIG. 1.

FIG. 20 is a perspective view of a connection between the terminal blockof the power of FIG. 18 with a terminal block of the battery pack ofFIG. 1.

FIG. 21 is a perspective view of a terminal block portion of anelectrical device.

FIG. 22 is another perspective view of the terminal block portion ofFIG. 21.

FIG. 23 is an isometric view of a terminal block of an electricaldevice.

FIG. 24 is a perspective view of a portion of an electrical device.

FIG. 25 is a side view of the portion of the electrical device as shownin FIG. 24.

FIG. 26 is a perspective view of power terminals shown in FIG. 24.

DETAILED DESCRIPTION

Before any independent embodiments of the invention are explained indetail, it is to be understood that the invention is not limited in itsapplication to the details of construction and the arrangement ofcomponents set forth in the following description or illustrated in thefollowing drawings. The invention is capable of other independentembodiments and of being practiced or of being carried out in variousways. Also, it is to be understood that the phraseology and terminologyused herein are for the purpose of description and should not beregarded as limiting.

The use of “including,” “comprising,” or “having” and variations thereofherein is meant to encompass the items listed thereafter and equivalentsthereof as well as additional items. Unless specified or limitedotherwise, the terms “mounted,” “connected,” “supported,” and “coupled”and variations thereof are used broadly and encompass both direct andindirect mountings, connections, supports, and couplings. Further,“connected” and “coupled” are not restricted to physical or mechanicalconnections or couplings.

Also, the functionality described herein as being performed by onecomponent may be performed by multiple components in a distributedmanner. Likewise, functionality performed by multiple components may beconsolidated and performed by a single component. Similarly, a componentdescribed as performing particular functionality may also performadditional functionality not described herein. For example, a device orstructure that is “configured” in a certain way is configured in atleast that way but may also be configured in ways that are not listed.

Furthermore, some embodiments described herein may include one or moreelectronic processors configured to perform the described functionalityby executing instructions stored in non-transitory, computer-readablemedium. Similarly, embodiments described herein may be implemented asnon-transitory, computer-readable medium storing instructions executableby one or more electronic processors to perform the describedfunctionality. As used in the present application, “non-transitorycomputer-readable medium” comprises all computer-readable media but doesnot consist of a transitory, propagating signal. Accordingly,non-transitory computer-readable medium may include, for example, a harddisk, a CD-ROM, an optical storage device, a magnetic storage device, aROM (Read Only Memory), a RAM (Random Access Memory), register memory, aprocessor cache, or any combination thereof.

Many of the modules and logical structures described are capable ofbeing implemented in software executed by a microprocessor or a similardevice or of being implemented in hardware using a variety of componentsincluding, for example, application specific integrated circuits(“ASICs”). Terms like “controller” and “module” may include or refer toboth hardware and/or software. Capitalized terms conform to commonpractices and help correlate the description with the coding examples,equations, and/or drawings. However, no specific meaning is implied orshould be inferred simply due to the use of capitalization. Thus, theclaims should not be limited to the specific examples or terminology orto any specific hardware or software implementation or combination ofsoftware or hardware.

As shown in FIG. 1, a battery pack 100 includes a housing 105 with asupport portion 110 and a terminal block 115. The housing 105 enclosescomponents of the battery pack 100 including battery cells, a batterycontroller, etc. The support portion 110 provides a slide-on arrangementwith a projection/recess 120 cooperating with a complementaryrecess/projection (not shown) of an electrical device (e.g., a powertool, an outdoor tool, etc.) or other electrical device (again,generally referred to herein as “devices” or a “device”) to mechanicallyconnect the battery pack 100 and the device.

With reference to FIG. 2, the terminal block 115 is operable toelectrically connect the battery pack 100 and the electrical device and,as illustrated, includes a positive battery terminal 205, a groundterminal 210, a charger terminal 215, a low-power terminal 220, apositive transmission terminal 225, a negative transmission terminal230, a positive receiver terminal 235, and a negative receiver terminal240. The positive battery terminal 205 and the ground terminal 210 areconnectable to power terminals of an electrical device, and provide amain discharging current for the operation of the electrical device. Thecharger terminal 215 and the ground terminal 210 are connected tocharging terminals of a charger and receive charging current to chargethe battery cells of the battery pack 100.

The ground terminal 210 may form a common reference between the batterypack 100 and the connected electrical device. The low-power terminal 220provides a low-power voltage supply to the electrical device to powercertain functions of the electrical device. For example, the low-powervoltage supply may be used to power a device controller, indicators(e.g., LEDs), a communication module, etc. of the electrical device.

The positive transmission terminal 225, the negative transmissionterminal 230, the positive receiver terminal 235, and the negativereceiver terminal 240 may together be referred to as “communicationterminals” of the battery pack 100. The communication terminals allowfor differential communication between the battery pack 100 and aconnected electrical device or charger. The illustrated communicationterminals are only used to either receive or transmit data but not both.In other embodiments, the communication terminals follow a full-duplexstandard (for example, RS485 standard).

In the illustrated construction, the communication terminals 225, 230,235, 240 are isolated from the power terminals 205, 210, 215, 220 toprovide a low-noise communication line. The communication terminals 225,230, 235, 240 provide sufficient information capacity between the devicecontroller and the battery pack controller.

FIG. 3 is a simplified block diagram of the battery pack 100. Thebattery pack 100 includes battery cells 305, a battery controller 310, abattery memory 315, a low-power circuit 320, other components 325, and abattery transceiver 330. The battery cells 305 may be any rechargeablebattery cell chemistry type, such as, for example, nickel-cadmium(NiCd), nickel-metal hydride (NiMH), Lithium (Li), Lithium-ion (Li-ion),other lithium-based chemistry, etc. In some embodiments, the batterypack 100 may include two or more battery cell strings connected inparallel, each having a number (e.g., five or more) of battery cellsconnected in series to provide a desired discharge output (e.g., nominalvoltage (e.g., 20 V, 40 V, 60 V, 80 V, 120 V) and current capacity). Inother embodiments, other configurations of battery cells 305 are alsopossible.

In some embodiments, the battery controller 310 may be implemented as amicroprocessor with a separate memory, such as the battery memory 315.In other embodiments, the battery controller 310 may be implemented as amicrocontroller (with battery memory 315 on the same chip). In otherembodiments, the battery controller 310 may be implemented usingmultiple processors. In addition, the battery controller 310 may beimplemented partially or entirely as, for example, a field programmablegate array (FPGA), an application specific integrated circuit (ASIC),etc., and the battery memory 315 may not be needed or be modifiedaccordingly.

In the example illustrated, the battery memory 315 includesnon-transitory, computer-readable memory that stores instructionsreceived and executed by the battery controller 310 to carry outfunctionality of the battery pack 100. The battery memory 315 mayinclude, for example, a program storage area and a data storage area.The program storage area and the data storage area may includecombinations of different types of memory, such as read-only memory andrandom-access memory.

In some embodiments, a discharging switch 335 is connected between thebattery cells 305 and the positive battery terminal 205. The batterycontroller 310 is operable to control (e.g., open and close) thedischarging switch 335 to control discharge of the battery cells 305. Insome embodiments, a charging switch 340 may also be connected betweenthe battery cells 305 and the charger terminal 215. The batterycontroller 310 is operable to control (e.g., open and close) thecharging switch 340 to control charging of the battery cells 305.

The discharging switch 335 and the charging switch 340 may beimplemented using bi-polar unction transistors, field-effect-transistors(FETs), etc. In some embodiments, the discharging switch 335 and thecharging switch 340 may be connected on the ground-side of the batterycells 305 between the battery cells 305 and the ground terminal 210. Insome embodiments (not shown), the ground terminal 210 may be split intoa charging path ground terminal and a discharging path ground terminal.

The low-power circuit 320 is connected between the battery cells 305 andthe low-power terminal 220. The low-power circuit 320 provides alow-power voltage supply at the low-power terminal 220 to a connectedelectrical device. In some embodiments, the battery controller 310 mayprovide control signals to the low-power circuit 320 to control theoperation of the low-power circuit 320. The low-power circuit 320 willbe described in more detail below with reference to FIGS. 4-5.

Other components 325 of the battery pack 100 may include, for example,voltage monitoring circuits to monitor the discharge voltage, currentmonitoring circuits to monitor discharge current, temperature sensors,pressure sensors, analog front-ends for cell balancing, etc. The batterycontroller 310 communicates with the other components 325 to monitor(e.g., receive sensor data) or to control the operation of the othercomponents 325.

In the illustrated example, the battery transceiver 330 is implementedas a differential communication transceiver (e.g., Texas InstrumentsSN65HVD7 Full Duplex RS-485 Transceiver). The battery transceiver 330receives a transmission signal 345 from the battery controller 310 andsends a receiver signal 350 to the battery controller 310.

The battery transceiver 330 is also connected to the communicationterminals (225, 230, 235, and 240). When the battery pack 100 transmitsa communication signal to a connected electrical device or charger, thebattery controller 310 sends the transmission signal 345 in addition toa transmission enable signal 355 to the battery transceiver 330. Whenthe battery transceiver 330 receives the transmission enable signal 355,the battery transceiver 330 converts the transmission signal 345 tocomplementary transmission signals at the positive transmission terminal225 and the negative transmission terminal 230. When the batterytransceiver 330 receives a receiver enable signal 360 from the batterycontroller 310, the battery transceiver 330 receives complementarysignals from the positive receiver terminal 235 and the negativereceiver terminal 240, converts the complementary signals to a singlereceiver signal 350, and sends the receiver signal 350 to the batterycontroller 310.

In other embodiments, rather than the battery transceiver 330, thebattery pack 100 may include separate transmitting and receivingcomponents, for example, a transmitter and a receiver.

A purpose of the low-power terminal 220 is to provide an independent,current limited, low-power path from which the device electronics maypower up. Accordingly, the device electronics may power up in acontrolled fashion. In addition, the illustrated low-power circuit 320consists of a low-power mode and a high-power mode. The low-power modeprovides a minimum amount of quiescent current when both the electricaldevice and the battery pack 100 are in a sleep state. During normaldischarge operations, the high power mode is enabled such that alldevice electronics may be operational.

FIG. 4 is a simplified circuit diagram of one embodiment of alow-current supply circuit 400 of the low-power circuit 320. In someembodiments, the low-current supply circuit 400 may be implemented usinga shunt regulator architecture. The low-current supply circuit 400includes a voltage loop 404 and a current loop 408 within the voltageloop 404. The low-current supply circuit 400 receives input power fromthe battery cells 305 over a positive terminal 412 and a negativeterminal 416. The nominal voltage range of the input power received overthe terminals 412 and 416 may be between, for example, 40 Volts (V) to80 V.

A fuse 420 is connected to the positive terminal 412 to act as a circuitbreaker when an excess current flows through the low-current supplycircuit 400. The fuse 420 may be rated for a current higher than acurrent output of the low-current supply circuit 400 to allow thelow-current supply circuit 400 to momentarily allow higher currentwithout nuisance tripping. In one example, the fuse 420 may be rated for200 mA at 125 V to allow an output current of 100 mA without nuisancetripping of the fuse 420.

The voltage loop 404 includes a field-effect-transistor (FET) 424, avoltage divider circuit 428, and a voltage regulator 432. The FET 424 isconnected between the battery cells 305 and the low-power terminal 220.In the illustrated embodiment, a drain of the FET 424 is connected tothe output of the fuse 420, and the source of the FET 424 is connectedto the low-power terminal 220. Pull up resistors 436 and 440 areconnected between the drain and the gate of the FET 424 to keep the FET424 biased in a manner to allow the FET 424 to conduct current betweenthe battery cells 305 and the low-power terminal 220. The gate of theFET 424 is modulated by the voltage regulator 432.

The voltage divider circuit 428 is connected between the low-powerterminal 220 and the ground terminal 210. The voltage divider circuit428 includes resistors 444, 448, 452, 456, and 460. The resistancevalues of the resistors 444-460 may be selected based on the desiredreferences voltage that may be provided to the voltage regulator 432. Inone example, the voltage regulator 432 may be a micro-power voltageregulator including a bipolar junction transistor and a Zener diodereference optimized for μA level bias currents. FIG. 5 is a simplifiedblock diagram of the voltage regulator 432 illustrating the pinconnections of the bipolar junction transistor 505 and the Zener diode510.

Returning to FIG. 4, the emitter of the bipolar junction transistor 505is connected to the cathode of the Zener diode 510. As a result, thebase-emitter junction of the bipolar junction transistor 505 is inseries with the Zener diode 510. The anode of the Zener diode 510 isconnected to ground. The collector of the bipolar junction transistor505 is connected to the gate of the FET 424. The base of the bipolarjunction transistor 505 receives the reference voltage from the voltagedivider circuit 428.

The voltage loop 404 operates to keep the voltage constant at thelow-power terminal 220. The collector current of the bipolar junctiontransistor 505 varies proportionally to the voltage presented at thebase terminal of the bipolar junction transistor 505. When the load atthe low-power terminal 220 is increased, the voltage across the voltagedivider circuit 428 decreases. As a result, the reference voltageprovided to the voltage regulator 432 decreases, which, in turn, reducesthe collector current. The collector current is also the current throughthe pull up resistors 436, 440. As such, the gate-source voltage of theFET 424 increases, which then conducts more current and increases thevoltage provided at the low-power terminal 220, which is also thevoltage across the voltage divider circuit 428. A stabilizer circuit 464may be used to form a compensation network to stabilize the voltage loop404.

The current loop 408 maintains operation of the low-current supplycircuit 400 in the event of excess current or a short circuit condition.The current loop 408 may be designed to have a foldback feature whichallows a first load current (e.g., 100 mA) for a pre-defined timedperiod before reducing the current output to a constant second loadcurrent (e.g., 50 mA). The current loop 408 includes a current regulatorcircuit 468, a current sensor 472 (e.g., a current sense resistor), anda timer circuit 476.

The current regulator circuit 468 includes a first bipolar junctiontransistor 480 and a second bipolar junction transistor 484. The firstbipolar junction transistor 480 modulates the gate voltage of the FET424 until the current sensor 472 indicates that the low-power circuit320 is outputting a first load current. The timer circuit 476 includinga resistor and a capacitor is connected between the base and emitter ofthe second bipolar junction transistor 484. The resistance andcapacitance values of the timer circuit 476 may be selected based on thedesired timing before which the load current drops from the first loadcurrent to the second load current.

Approximately at the same time the first bipolar junction transistor 480is modulating the FET 424, the capacitor of the timer circuit 476 isbeing charged. For example, the capacitor and resistor values of thetimer circuit 476 may be selected such that the capacitor of the timercircuit 476 charges in 1 s. When the capacitor of the timer circuit 476is charged, the second bipolar junction transistor 484 starts conductingcurrent thereby producing a voltage drop across the second bipolarjunction transistor 484. The first bipolar junction transistor 480 thenmodulates the FET 424 until the current output reaches the second loadcurrent (e.g., 50 mA).

FIG. 6 is a simplified circuit diagram of another embodiment of alow-current supply circuit 600 of the low-power circuit 320. Thelow-current supply circuit 600 may function in a manner similar to thelow-current supply circuit 400. The low-current supply circuit 600includes a voltage loop 604 and a current loop 608 within the voltageloop 604. The low-current supply circuit 600 receives input power fromthe battery cells 305 over a positive terminal 612 and a negativeterminal 616. The nominal voltage range of the input power received overthe terminals 612 and 616 may be between, for example, 40 Volts (V) to80 V.

A fuse 620 is connected to the positive terminal 612 to act as a circuitbreaker when an excess current flows through the low-current supplycircuit 600. The fuse 620 may be rated for a current higher than acurrent output of the low-current supply circuit 600 to allow thelow-current supply circuit 600 to momentarily allow higher currentwithout nuisance tripping. In one example, the fuse 620 may be rated for200 mA at 125 V to allow an output current of 100 mA without nuisancetripping of the fuse 620.

The voltage loop 604 includes a field-effect-transistor (FET) 624, avoltage divider circuit 628, and a voltage regulator 632. The FET 624 isconnected between the battery cells 305 and the low-power terminal 220.In the illustrated embodiment, a drain of the FET 624 is connected tothe output of the fuse 620, and the source of the FET 624 is connectedto the low-power terminal 220. Pull up resistors 636 and 640 areconnected between the drain and the gate of the FET 624 to keep the FET624 biased in a manner to allow the FET 624 to conduct current betweenthe battery cells 305 and the low-power terminal 220. The gate of theFET 624 is modulated by the voltage regulator 632.

The voltage divider circuit 628 is connected between the low-powerterminal 220 and the ground terminal 210. The voltage divider circuit628 includes resistors 644, 648, 652, and 656. The resistance values ofthe resistors 644-656 may be selected based on the desired referencevoltages that may be provided to the voltage regulator 632. As describedabove, the voltage regulator 632 may be a micro-power voltage regulatorincluding a bipolar junction transistor and a Zener diode referenceoptimized for μA level bias currents (for example, as shown in FIG. 5).

The emitter of the bipolar junction transistor 505 is connected to thecathode of the Zener diode 510. As a result, the base-emitter junctionof the bipolar junction transistor 505 is in series with the Zener diode510. The anode of the Zener diode 510 is connected to ground. Thecollector of the bipolar junction transistor 505 is connected to thegate of the FET 624. The base of the bipolar junction transistor 505receives the reference voltage from the voltage divider circuit 628.

The voltage loop 604 operates to keep the voltage constant at thelow-power terminal 220. The collector current of the bipolar junctiontransistor 505 varies proportionally to the voltage presented at thebase terminal of the bipolar junction transistor 505. When the load atthe low-power terminal 220 is increased, the voltage across the voltagedivider circuit 628 decreases. As a result, the reference voltageprovided to the voltage regulator 632 decreases, which, in turn, reducesthe collector current. The collector current is also the current throughthe pull up resistors 636, 640. As such, the gate-source voltage of theFET 624 increases, which then conducts more current and increases thevoltage provided at the low-power terminal 220, which is also thevoltage across the voltage divider circuit 628. A stabilizer circuit 664may be used to form a compensation network to stabilize the voltage loop604.

The current loop 608 protects the low-current supply circuit 600 in theevent of excess current or a short circuit condition. The current loop608 may be designed to have a fold-back feature which allows a firstload current (e.g., 180 mA) for a pre-defined time period (e.g., time)before reducing the current output to a constant second load current(e.g., 60 mA). The current loop 608 includes a current regulator circuit668, a current sensor 672 (e.g., current sense resistors), and a timercircuit including a resistor 676 and a capacitor 680.

The current regulator circuit 668 includes a first bipolar junctiontransistor 688 and a second bipolar junction transistor 684. The firstbipolar junction transistor 688 modulates the gate voltage of the FET624 until the current sensor 672 indicates that the low-current supplycircuit 600 is outputting a first load current. The timer circuit,including a resistor 676 and a capacitor 680, is connected between thebase and emitter of the second bipolar junction transistor 684. Theresistance and capacitance values of the timer circuit may be selectedbased on the desired timing before which the load current drops from thefirst load current to the second load current.

Approximately at the same time the first bipolar junction transistor 688is modulating the FET 624, the capacitor 680 of the timer circuit 676 isbeing charged. For example, the capacitor 680 and resistor 676 values ofthe timer circuit may be selected such that the capacitor 680 of thetimer circuit charges in 700 ms. When the capacitor 680 of the timercircuit is charged, the second bipolar junction transistor 684 startsconducting current thereby producing a voltage drop across the firstbipolar junction transistor 687. The second bipolar junction transistor684 then modulates the FET 624 until the current output reaches thesecond load current (e.g., 60 mA).

FIG. 7 is a simplified circuit diagram of one embodiment of ahigh-current supply circuit 700 of the low-power circuit 320. In theexample illustrated, the high-current supply circuit 700 includes a fuse704 an input switch 708, an enable switch 712, a flyback converter 716,a startup circuit 720, a clamp circuit 724, a primary switch 728, and atransformer circuit 732. The fuse 704 protects the high-current supplycircuit 700 from short-circuit faults. The fuse 704 may have a nominalrating of, for example, 500 mA. The fuse 704 may be dimensioned to allowfor full power operation at low line input.

When an enable input 736, for example, a wake-up signal, is applied tothe enable switch 712, the enable switch 712 closes the input switch708, thereby allowing current from the battery cells 305 to flow to thehigh-current supply circuit 700. The startup circuit 720 provides aninitial power supply to operate the converter 716.

FIG. 8 illustrates one example embodiment of the startup circuit 720. Inthe example illustrated, the startup circuit 720 includes a firstresistor 804, a second resistor 808, a third resistor 812, a switch 816,a capacitor 820, and a diode 824. The first resistor 804, the switch 816and the capacitor 820 are connected in series between the positive powersupply 828 and ground 832. The second resistor 808, the third resistor812 and the diode 824 are connected in series between the positive powersupply 828 and ground 832 and in parallel to the first resistor 804, theswitch 816, and the capacitor 820.

Initially, the voltage across the capacitor 820 may be zero. The secondresistor 808, the third resistor 812, and the diode form, for example,15V reference on a gate of the switch 816. As power is applied to thestartup circuit, the switch 816 is turned on. The capacitor 820 is thencharged up and by the drain current of the switch 816. When the voltageacross the capacitor 820 is, for example, approximately 8V, the startupcircuit 720 powers the converter 716.

Returning to FIG. 7, when the converter 716 receives the startup power,the converter 716 starts switching and modulating a gate of the primaryswitch 728. Eventually, the converter 716 starts up and regulates to,for example, approximately 15V. At this point, the startup circuit 720may be turned off and the converter 716 may be powered by the output ofthe high-current supply circuit 700.

The clamp circuit 724 manages energy in the leakage inductance of thetransformer circuit 732. The transformer circuit 732 includes a primarywinding 740, and three secondary windings 744, 748, and 752. When theprimary switch 728 is closed, the voltage drawn across the primarywinding 740 is stepped down and provided to the secondary windings 744,748, and 752. The secondary winding 744 provides the low-power voltagesupply at the low-power voltage supply terminal 220. The secondarywindings 748 and 752 provide power to the discharging switch 335 and thecharging switch 340 of the battery pack 100. In some embodiments, a lowdropout regulator (LDO) may be used instead of the transformer circuit732 to step down the voltage.

When there is an activity that enables the high-current supply circuit700 of the low-power circuit 320, the high-current supply circuit 700may remain enabled, for example, for 100 ms from last known activitybefore disabling the high-current supply circuit 700 and enabling thelow-current supply circuit 600. This may, for example, allow the batterypack 100 sufficient time for an orderly shutdown, to attempt acommunications restart in the event of a fault.

With reference to FIG. 9, a device terminal block 900 includes apositive power terminal 905, a ground terminal 910, a low-power terminal920, a positive transmission terminal 925, a negative transmissionterminal 930, a positive receiver terminal 935, and a negative receiverterminal 940. As described above, the positive power terminal 905 andthe ground terminal 910 are connected to power terminals (i.e., positivebattery terminal 205 and ground terminal 210) of the battery pack 100 toreceive a main discharging current for the operation of the electricaldevice. The low-power terminal 920 receives a low-power voltage supplyfrom the low-power terminal 220 of the battery pack 100 to power certainfunctions of the electrical device.

The positive transmission terminal 925, the negative transmissionterminal 930, the positive receiver terminal 935, the negative receiverterminal 940 may together be referred to as “communication terminals” ofthe electrical device. The communication terminals allow fordifferential communication between the battery pack 100 and theelectrical device. As with the communication terminals of the batterypack 100, the illustrated device communication terminals are only usedto either receive or transmit data but not both. In other embodiments,the device communication terminals follow a full-duplex standard (forexample, RS485 standard).

FIG. 10 is a simplified block diagram of an electrical device 1000. Theelectrical device 1000 includes a device controller 1010, a devicememory 1015, a load (e.g., a motor 1020), a load (motor) controller1025, and a device transceiver 1030. The motor 1020 may be a brushed orbrushless motor and is controlled by the motor controller 1025.

The motor controller 1025 may be a switch bridge including FETs thatcontrol the operation of the motor 1020. The motor controller 1025 mayalso include position sensors and other motor sensors. The motorcontroller 1025 may send positional information of the motor 1020 to thedevice controller 1010 and may receive control signals from the devicecontroller 1010.

The device controller 1010 may be implemented in various ways includingways similar to those described above with respect to the batterycontroller 310. Likewise, the device memory 1015 may be implemented invarious ways including ways that are similar to those described withrespect to the battery memory 315. The device memory 1015 may storeinstructions received and executed by the device controller 1010 tocarry out the functionality. The device controller 1010 receivesoperating power from the low-power terminal 920. In some embodiments,the device controller 1010 and the battery pack controller 310 may beimplemented on a single controller.

In some embodiments, a discharging switch 1035 is connected between thepositive power terminal 1005 and the motor controller 1025. The devicecontroller 1010 operates to control (e.g., opens and closes) thedischarging switch 1035 to control the discharge from the battery pack100. The discharging switch 1035 may be implemented using bi-polarjunction transistors, field-effect-transistors (FETs), etc. In someembodiments, the discharging switch 1035 may be connected on theground-side of the motor controller 1025 between the motor controller1025 and the ground terminal 910.

In the illustrated example, the device transceiver 1030 is implementedas a differential communication transceiver (e.g., Texas InstrumentsSN65HVD7 Full Duplex RS-485 Transceiver). The device transceiver 1030receives a transmission signal 1040 from the device controller 1010 andsends a receiver signal 1045 to the device controller 1010. The devicetransceiver 1030 is also connected to the communication terminals.

When the electrical device 1000 transmits a communication signal to aconnected battery pack 100, the device controller 1010 sends thetransmission signal 1040 in addition to a transmission enable signal1050 to the device transceiver 1030. When the device transceiver 1030receives the transmission enable signal 1050, the device transceiver1030 converts the transmission signal 1040 to complementary transmissionsignals at the positive transmission terminal 925 and the negativetransmission terminal 930.

When the device transceiver 1030 receives a receiver enable signal 1055from the device controller 1010, the device transceiver 1030 receivescomplementary signals from the positive receiver terminal 935 and thenegative receiver terminal 940, converts the complementary signals to asingle receiver signal 1045, and sends the receiver signal 1045 to thedevice controller 1010.

In other embodiments, rather than the device transceiver 1030, thedevice 1000 may include separate transmitting and receiving components,for example, a transmitter and a receiver.

During a sleep state, the battery pack 100 may disable the receiverterminals 235 and 240 by sending a receiver disable signal 360. In someembodiments, the device transceiver 1030 may send a wake-up pulse to thebattery pack 100 to request operational power for the electrical device1000. The battery pack 100 may include a wake-up circuit to detect thewakeup pulse, which, in turn, will drive an interrupt to the batterycontroller 310. The battery controller 310 enables the receiverfunctions of the battery transceiver 330 upon receiving the interrupt.

With reference to FIG. 11, a charger terminal block 1100 includes aground terminal 1110, a charger terminal 1115, a positive transmissionterminal 1125, a negative transmission terminal 1130, a positivereceiver terminal 1135, and a negative receiver terminal 1140. Thecharger terminal 1115 and the ground terminal 1110 are connected toterminals (e.g., the charger terminal 215 and ground terminal 210) ofthe battery pack 100 to charge the battery cells 305 of the battery pack100. A low-power terminal may not be needed, because the chargerindependently receives operating power from an external power source.

The positive transmission terminal 1125, the negative transmissionterminal 1130, the positive receiver terminal 1135, the negativereceiver terminal 1140 may together be referred to as “communicationterminals” of the charger. The communication terminals allow fordifferential communication between the battery pack 100 and the charger.As with the communication terminals of the battery pack 100 and theelectrical device 1000, the illustrated charger communication terminalsare only used to either receive or transmit data but not both. In otherembodiments, the charger communication terminals follow a full-duplexstandard (for example, RS485 standard).

FIG. 12 is a simplified block diagram of a charger 1200. The charger1200 includes a charger controller 1210, a charger memory 1215, a powerconverter 1220, a power source connector 1225, and a charger transceiver1230. The power source connector 1225 connects to an external powersource (e.g., wall outlet) to receive power for charging a battery pack100. The power converter 1220 converts the AC power received from theexternal power source to a DC power to charge the battery pack 100. Thepower converter 1220 may receive control signals from the chargercontroller 1210 to control the charging operation.

The charger controller 1210 may be implemented in various ways includingways similar to those described above with respect to the batterycontroller 310. Likewise, the charger memory 1215 may be implemented invarious ways including ways similar to those described above withrespect to the battery memory 315. The charger memory 1215 may storeinstructions received and executed by the charger controller 1210 tocarry out the functionality. The charger controller 1210 receivesoperating power from the power converter 1220.

In some embodiments, a charging switch 1235 is connected between thecharger terminal 1115 and the power converter 1220. The chargercontroller 1210 controls (e.g., opens and closes) the charging switch1235 to control charging of the battery pack 100. The charging switch1235 may be implemented using bi-polar junction transistors,field-effect-transistors (FETs), etc. In some embodiments, the chargingswitch 1235 may be connected on the ground-side of the power converter1220 between the power converter 1220 and the ground terminal 1110. Thecharger controller 1210 may monitor the positive power terminal 1205 todetermine a state of charge of the battery pack 100. In someembodiments, back-to-back MOSFETs may be used for the charging switch1235. MOSFETs include a body diode which allows a small amount ofcurrent to flow through even when the MOSFET is open (i.e., turned off).Connecting a second MOSFET back-to-back with a first MOSFET such thatthe body diodes are pointing in the opposite direction may ensure thatno current flows through the charging terminal 1115 when the MOSFETs areopen (i.e., turned off).

In the illustrated example, the charger transceiver 1230 is implementedas a differential communication transceiver (e.g., Texas InstrumentsSN65HVD7 Full Duplex RS-485 Transceiver). The charger transceiver 1230receives a transmission signal 1240 from the charger controller 1210 andsends a receiver signal 1245 to the charger controller 1210. The chargertransceiver 1230 is also connected to the communication terminals.

When the charger 1200 transmits a communication signal to a connectedbattery pack 100, the charger controller 1210 sends the transmissionsignal 1240 in addition to a transmission enable signal 1250 to thecharger transceiver 1230. When the charger transceiver 1230 receives thetransmission enable signal 1250, the charger transceiver 1230 convertsthe transmission signal 1240 to complementary transmission signals atthe positive transmission terminal 1125 and the negative transmissionterminal 1130.

When the charger transceiver 1230 receives a receiver enable signal 1155from the charger controller 1210, the charger transceiver 1230 receivescomplementary signals from the positive receiver terminal 1135 and thenegative receiver terminal 1140, converts the complementary signals to asingle receiver signal 1145, and sends the receiver signal 1145 to thecharger controller 1210.

In other embodiments, rather than the charger transceiver 1230, thecharger 1200 may include separate transmitting and receiving components,for example, a transmitter and a receiver.

Whenever the battery pack 100 connects to an electrical device 1000 or acharger 1200 for the first time, a full authentication process may bedone before the electrical device 1000 or the charger 1200 may begranted permission for deployment. A quick re-authentication featureenables a fast means for devices to re-engage after a sleep eventwithout requiring a full authentication.

This quick re-authentication process starts after a successful fullauthentication, in which the device controller 1010 (or a chargercontroller 1210) generates a random number (or a series of randomnumbers) and shares those numbers with the battery pack 100. Thesenumbers are used as quick “keys” to re-authenticate after waking fromsleep. If, after waking, the device controller 1010 loads one of thosevalues into the quick authentication location, then the battery pack 100considers itself authenticated to the electrical device 1000. If aninvalid value is loaded, then a full authentication is required.

To accomplish this, the battery pack 100 has a “QUICK AUTHENTICATION”memory location, as well as a “SET QUICK AUTHENTICATION” location. TheSET QUICK AUTHENTICATION may be write-only and may only able to bewritten after the battery pack 100 considers itself authenticated to theelectrical device 1000 (or the charger 1200). The battery pack 100 mayno longer consider itself fully authenticated once the batterytransceiver 330 is put to sleep; however, the quick authentication isavailable unless the battery pack 100 has explicitly been instructed todrop the authentication session. This may happen, for example, when theelectrical device 1000 detects that the battery pack 100 is about to beejected and thus requests the battery pack 100 to drop the session.

QUICK AUTHENTICATION may be write-only and may only able to be writtenonce prior to requiring a full authentication. This may be one of theonly memory locations that is writeable when the battery pack 100 is notin an authenticated state. After QUICK AUTHENTICATION is written (onceonly), the value in QUICK AUTHENTICATION is compared to the value in SETQUICK AUTHENTICATION. If they match, the battery pack 100 considersitself authenticated. If they do not match, then the battery pack 100requires a full authentication prior to any other communications. Thisprocess is illustrated in FIG. 13.

In order to facilitate the power down process of the system, a latchengagement system may be incorporated into a latch interface. Thisengagement system may consist of a switch which will inform the devicecontroller 1010 that the battery pack 100 is about to be removed fromthe electrical device 1000. Thus, the electrical device 1000 may enact ashutdown procedure of its power path and inform the battery pack 100 ofthe same.

When the communication session between the battery pack 100 and theelectrical device 1000 is terminated, the battery pack 100 drops theauthenticated session, disables the battery transceiver 330, and enablesa wakeup circuit. The battery pack 100 may need a wake-up signal throughthe battery transceiver 330 and then re-authentication to once againbegin a valid communications session.

When the latch of the electrical device 1000 is engaged with the batterypack 100, the electrical device 1000 enters a discovery mode. In thediscovery mode, the electrical device 1000 sends a wake up pulse andbegins an authentication process. When the latch is not engaged, theelectrical device 1000 enters a sleep mode, in which the electricaldevice 1000 may be woken up when the latch is engaged.

At a physical interface level (i.e., physical interface between abattery pack 100 and the charger 1200 or the electrical device 1000), acommunications session timeout may be enforced. Because full duplexcommunications are permitted, there are separate timeout rules for boththe transmitter and the receiver. In short, communications must occur ata rate of at least every 10 msec. If communications do not happen within10 msec, then the physical interface may timeout the session. In orderto allow multiple retries within 10 msec, the communications period maybe set at 4 msec intervals. Thus, if a fault happens, at least one retryis permitted before the physical interface will timeout and fault thecommunications session.

A timing of both the transmitter and the receiver is illustrated inFIGS. 14-15. The table below is a further explanation of the timeoutconditions.

Role Period Action Rationale Transmitter 4 msec Packet byte Normal commsoccurring every period PI_ACK If receiving a packet that is longer thanthe period, then transmit the PI_ACK to indicate the session is stillvalid PI_ERROR If an error condition occurs at the PI level, relay thisgeneric information to the other device Receiver 10 msec Drop If thereceiver has not received communications A valid byte session A PI_ACK(as first byte) A PI_ERROR (as first byte) Assume the communicationssession is faulted

Referring to FIGS. 9 and 11, a thickness of one or more male terminalsof an electrical device or a battery charger can be selected to optimizeweight, strength, and durability characteristics of the terminal(s). Insome embodiments, the terminals have a thickness of between 0.8millimeter (mm) and 1.2 mm. In one example, the terminals have athickness of about 1 mm.

In some constructions, male terminals 1110-1140 are (see FIGS. 9 and 11)generally flat plates, including opposite axially-extending facesconnected by opposite axially-extending edges. Each terminal 1110-1140extends from the housing to a free end. In some constructions (see FIG.16), terminals (including power terminals 905, 910) extend above thestructure of the guide rails 1260.

In some embodiments (see, e.g., FIGS. 16 and 18), the terminals 905, 910may be constructed to increase the strength, durability, etc., to, forexample, protect against damage during drops or during handling of theelectrical devices. In one construction (see FIG. 16), a terminal (e.g.,the positive power terminal 905, the ground terminal 910, etc.) includesa wing (e.g., a positive terminal wing 1605, a ground terminal wing1610, etc.).

The illustrated positive terminal wing 1605 is integrally formed withthe positive power terminal 905 and includes a connecting portion 1615and a ledge portion 1620. In the illustrated construction, the ledgeportion 1620 extends transverse (e.g., substantially perpendicular) tothe positive power terminal 905 towards a first side edge of the deviceterminal block 900. The connecting portion 1615 transitions (e.g.,curves) between and connects the positive power terminal 905 and theledge portion 1620.

Similarly, the illustrated ground terminal wing 1610 is integrallyformed with the ground terminal 910 and includes a connecting portion1625 and a ledge portion 1630. In the illustrated construction, theledge portion 1630 extends transverse (e.g., substantiallyperpendicular) to the ground terminal 910 toward an opposite second sideedge of the device terminal block 900. The connecting portion 1625transitions (e.g., curves) between and connects the ground terminal andthe ledge portion 1630.

The terminal wings 1605, 1610 may be provided such that they extend onlypart of the axial length (e.g., between about 25% and about 50% of theaxial length) of the associated terminal 905, 910, respectively. Onlythe part of the terminal 905, 910 extending beyond the associatedterminal wing 1605, 1610 may be received in the female terminal of thebattery pack terminal block 115 (see FIGS. 19-20). The terminal wings1605, 1610 do not interfere with electrical connection between theterminals of the electrical device and the battery pack. In otherembodiments, the terminal wings 1605, 1610 may extend the full axiallength of the associated terminal 905, 910 respectively.

Referring to FIG. 17, the battery pack housing 105 may be constructed toaccommodate the terminal wing(s) 1605, 1610. The housing 105 includes apositive power terminal opening 1705 and a ground terminal opening 1710to receive the positive power terminal 905 and the ground terminal 910,respectively. In the illustrated construction, the positive powerterminal opening 1705 includes a wing-receiving portion 1715 shaped toreceive the positive terminal wing 1605. Similarly, the illustratedground terminal opening 1710 includes a wing-receiving portion 1720shaped to receive the ground terminal wing 1610. The wing 1605, 1610 mayengage a wall of the associated wing-receiving portion 1715, 1720 to,for example, transfer forces, limit relative movement between thebattery pack and the electrical device, etc., during drops or duringhandling of the electrical devices.

A battery pack housing (not shown) which is not constructed toaccommodate the winged terminals 905, 910 (e.g., without thewing-receiving portion 1710, 1720) may be prevented from electricallyconnecting with an electrical device or a charger including such wingedterminals 905, 910. The winged terminals 905, 910 may contribute to alock-out feature to inhibit electrical connection of incompatiblebattery packs and electrical devices or chargers.

In some embodiments, additional structure (e.g., support ribs, dimples,etc., having different shapes, constructions) may be provided on thepower terminal(s) instead of or in addition to the terminal wing(s)1605, 1610. Referring to FIG. 18, the positive power terminal 905 andthe ground terminal 910 are provided with one or more support ribs 1805on one face. The rib(s) 1805 provide additional support to each terminal905, 910.

In some embodiments (see FIG. 18), the ribs 1805 are separate from andattached to the terminal(s) 910. In such constructions, the ribs 1805may be formed of a different material (e.g., plastic) than theterminal(s) 905, 910 (formed of metal). In some embodiments (see FIGS.24-26), the ribs 1805 are integrally formed with the terminal(s) 905,910 and of the same material (e.g., metal).

With multiple support ribs 1805, the ribs 1805 are spaced apart (e.g.,substantially equidistant) along the face of the terminal 905, 910. Theribs 1805 may be provided such that they extend only part of the axiallength (e.g., between about 25% and about 50% the axial length (e.g.,about 33%)) of the associated terminal 905, 910. Only the part of theterminal 905, 910 extending beyond the ribs 1805 is received in thefemale terminals of the battery pack terminal block 115 (see FIGS.19-20). The ribs 1805 do not inhibit electrical connection between theterminals of the electrical device and the battery pack. In otherembodiments, the ribs 1805 may extend the full axial length of theassociated terminal 905, 910.

Referring to FIGS. 19-20, the battery pack housing 105 is constructed toaccommodate the terminal(s) 905, 910 with the rib(s) 1805. Particularly,the width of the positive power terminal opening 1705 and the groundterminal opening 1710 is increased to accommodate the ribs 1805.

A battery pack housing (not shown) which is not constructed toaccommodate the terminal(s) 905, 910 with rib(s) 1805 (e.g., without theincreased width terminal opening(s) 1705, 1710) may be prevented fromelectrically connecting with an electrical device or a charger includingsuch terminals 905, 910. The terminal(s) 905, 910 with rib(s) 1805 maycontribute to a lock-out feature to inhibit electrical connection ofincompatible battery packs and electrical devices or chargers.

In some constructions (see FIGS. 24-26), one or more terminal(s) (e.g.,the terminals 905, 910) include wings 1605, 1610, respectively, and ribs1805. The terminal wings 1605, 1610 may be provided such that theyextend only part of the axial length (e.g., between about 75% and about95% (e.g., about 91%) of the axial length) of the associated terminal905, 910, respectively. Likewise, the ribs 1805 may be provided suchthat they extend only part of the axial length (e.g., between about 25%and about 50% the axial length (e.g., about 33%)) of the associatedterminal 905, 910. As shown, the length of the wings 1605, 1610 and theribs may be different. In other embodiments, the terminal wings 1605,1610 and the ribs 1805 may extend the full axial length of theassociated terminal 905, 910 respectively.

In the illustrated construction, each wing 1605, 1610 is formed with theassociated terminal 905, 910. The illustrated ribs 1805 are also formedwith the associated terminal 905, 910, for example, by stamping, suchthat the opposite face of the terminal 905, 910 has correspondingrecesses 1810.

It should be understood that, in other constructions (not shown), thebattery pack may include male terminals and the electrical device andthe charger may include female terminals. In such constructions (notshown), the pack male terminal(s) may include the wing(s) and/or thesupport rib(s), and the device housing or the charger housing mayinclude the terminal opening to accommodate the wing(s), the rib(s),etc.

In some embodiments, additional support structures are added to thedevice housing and the battery pack housing 105. FIGS. 21-22 illustratea device housing 2105 including a terminal block portion 2110. Theterminal block portion 2110 includes ribs 2115 positioned outside eachside surface of the device terminal block 900.

Referring to FIG. 17, the pack housing 105 is constructed to accommodatethe ribs 2115. Cutouts 2120 in the pack housing 105 receive the ribs2115 when the battery pack is attached to the electrical device.

FIG. 23 illustrates another embodiment of a device housing 2305including a terminal block portion 2310. The device housing 2305includes side surface ribs 2315 on either side (that is, a first sideand a second side) of the housing 2305. Support ribs 2320 are positionedon either side of the terminal block portion 2310. The illustratedsupport ribs 2320 are provided on an inside portion compared to the sidesurface ribs 2315 on the device housing 2305.

Additional connection ribs 2325 are positioned between the support ribs2320 and the side surface ribs 2315. The connection ribs 2325 connectthe support ribs 2320 to the side surface ribs 2315 to support thesupport ribs 2320. The rib arrangement including the side surface ribs2315, the support ribs 2320, and the connection ribs 2325 provideadditional support to the terminal block portion 2310 to, for example,protect against damage during drops or during handling of the electricaldevices.

Thus, the invention may provide, among other things, a battery packterminal configuration. The configuration may include a low-powerterminal and/or a row of one or more communication terminals spaced froma row of power terminals. The invention may provide a battery packincluding a low power circuit operable to provide a reduced voltage fromall of the battery cells of the battery pack to the powered electricaldevice. The invention may provide a terminal (e.g., a male bladeterminal) with terminal support structure (e.g., a wing, one or moreribs, etc.).

One or more independent features and/or independent advantages of theinvention may be set forth in the claims.

What is claimed is:
 1. An electrical combination comprising: a batterypack including: a pack housing, a plurality of battery cells supportedby the pack housing, and a pack terminal electrically connected to thebattery cells; and an electrical device including: a device housing, acircuit supported by the device housing, and a device terminalelectrically connected to the circuit and electrically connectable tothe pack terminal to electrically connect the circuit to one or morebattery cells; one of the pack terminal and the device terminalincluding: a terminal blade extending along an axis and having oppositeaxially-extending faces connected by opposite axially-extending edges,and a terminal support portion extending transverse to the axis andbeyond an associated face.
 2. The electrical combination of claim 1,wherein the device terminal includes the terminal blade and the terminalsupport portion.
 3. The electrical combination of claim 2, wherein thebattery pack includes a pack positive power terminal and a pack groundterminal, wherein the electrical device includes a device positive powerterminal electrically connectable to the pack positive power terminaland a device ground terminal electrically connectable to the pack groundterminal, wherein the device positive power terminal includes theterminal blade and the terminal support portion, wherein the deviceground terminal includes a terminal blade and a terminal supportportion, and wherein each terminal support portion includes a transversewing connected to one edge.
 4. The electrical combination of claim 3,wherein an opposite one of the pack housing and the device housingdefines an opening having a first portion receiving the terminal bladeand a transverse second portion receiving the transverse wing.
 5. Theelectrical combination of claim 3, wherein the electrical deviceincludes a terminal block having a first side and an opposite secondside, wherein the device positive power terminal is positioned towardthe first side, the wing of the device positive power terminal extendingtoward the first side, and wherein the device ground terminal ispositioned toward the second side, the wing of the device groundterminal extending toward the second side.
 6. The electrical combinationof claim 3, wherein each terminal support portion includes at least onerib on the associated face.
 7. A terminal block for one of a batterypack and an electrical device electrically connectable to the batterypack along an axis, the terminal block comprising: a housing; and aplurality of terminals including a positive power terminal and a groundterminal, at least one terminal including a terminal blade extendingalong the axis and having opposite axially-extending faces connected byopposite axially-extending edges, and a terminal support portionextending transverse to the axis and beyond an associated face.
 8. Theterminal block of claim 7, wherein the positive power terminal includesa terminal blade and a terminal support portion, wherein the groundterminal includes a terminal blade and a terminal support portion, andwherein each terminal support portion includes a transverse wingconnected to one edge.
 9. The terminal block of claim 8, wherein theterminal block has a first side and an opposite second side, wherein thepositive power terminal is positioned toward the first side, theterminal support portion of the positive power terminal extending towardthe first side, and wherein the ground terminal is positioned toward thesecond side, the terminal support portion of the ground terminalextending toward the second side.
 10. The terminal block of claim 9,wherein each terminal support portion also includes at least one rib onthe associated face.
 11. The terminal block of claim 7, wherein theterminal support portion includes at least one rib on the associatedface.
 12. The terminal block of claim 7, wherein the terminal blade hasan axial length between a free end and an opposite end, the supportportion extending from proximate the opposite end toward the free end adistance less than the axial length of the terminal blade.
 13. Theterminal block of claim 12, wherein the distance is between about 25%and about 50% of the axial length.
 14. The terminal block of claim 12,wherein the distance is between about 75% and about 95% of the axiallength.
 15. A terminal for one of a battery pack and an electricaldevice electrically connectable to the battery pack along an axis, theterminal comprising: a terminal blade extending along the axis andhaving opposite axially-extending faces connected by oppositeaxially-extending edges; and a terminal support portion extendingtransverse to the axis and beyond an associated face.
 16. The terminalof claim 15, wherein the terminal support portion includes a transversewing connected to one edge, wherein the transverse wing is formed withthe terminal blade.
 17. The terminal of claim 16, wherein the terminalblade has an axial length between a free end and an opposite end, thewing extending from proximate the opposite end toward the free end adistance between about 25% and about 50% of the axial length.
 18. Theterminal of claim 16, wherein the terminal blade has an axial lengthbetween a free end and an opposite end, the wing extending fromproximate the opposite end toward the free end a distance between about75% and about 95% of the axial length.
 19. The terminal of claim 16,wherein the terminal support portion also includes at least one rib onthe associated face.
 20. The terminal of claim 15, wherein the terminalblade has an axial length between a free end and an opposite end, theterminal support portion extending from proximate the opposite endtoward the free end a distance less than the axial length of theterminal blade.